255ext HF Start

[performance]

Try just using .5 seconds of Preflow or less. See if that makes a difference. Also touch your tungsten to the work piece before briefly trying to make a start. See if this helps.

[labmaster02]

I usually set the preflow to .5, but I even tried 0 and as much as 3 seconds still the same. It will start every time if I touch the tungsten first, but it kind of takes away from the HF starts

I tried another torch and it does the same. I also noticed it's much worse on DC, but also does it in AC just not as bad

[Rambozo]

I usually set the preflow to .5, but I even tried 0 and as much as 3 seconds still the same. It will start every time if I touch the tungsten first, but it kind of takes away from the HF starts

I tried another torch and it does the same. I also noticed it's much worse on DC, but also does it in AC just not as bad

It sounds like you get HF starts, so it's not a complete fail. It almost sounds like you have to bleed off some kind of charge before the machine resets for a clean start. There should be no spark when you touch the work with the pedal up.
Do this, before you even hit the pedal, touch the work with the tungsten and see if there is any spark, then hold a 1/16 - 1/8" gap and hit the pedal. What happens? Another test is with the torch away from the work, tap the pedal and release it, then while the postflow is going position the torch as before and hit the pedal. What happens? Increase the postflow duration if you need more time to do this test. That might shed some light into what is going on. Of course be sure you do this with a fresh tungsten and make sure you have a good ground. Let us know what happens.

[performance]

Miller Inverters will even do this. It's something that can happen from time to time. I am not a technician, but am familiar with this sort of thing. I ran across an article the other day by Miller or Lincoln explaining this phenomenon on inverters.

[labmaster02]

Rambozo
I'll try your suggestions when I get home today. I also have a Millermatic 211 MIG and that one does the same thing, after welding if I touch the wire to the metal it sparks, sometimes enough to darken the helmet. Miller says it's residual voltage from the caps. I know it's a different machine with the transformer though.

Performance
I read an article from Miller talking about having to scratch the tungsten across the metal if it doesn't start. They blame it on either the tungsten or the material is contaminated. I've considered this too but if even happens with clean metal and tungsten.

Something I noticed last night while trying this was the HF was erratic. Even when it started, the time varied, it wasn't always the .5 setting on the preflow, Sometimes it was noticeably longer even when it did work

Thanks for all the help

[rick9345]

Don't know about 250EXT,but on my 250EX and Miller Syncrowave 250 and my old Dialarc all have points and sensitive to point gap setting for smooth consistant HF starts.
When using pedal set start amps at 0 and end amps at 0 and be in 2T
Gas leak argon contamination??

Suggest call Everlast support.
They have been very helpful for me, have info in hand ,ser#, settings etc.

[labmaster02]

255ext has solid state HF no points

[performance]

A few 255EXT's were produced with points. If you see a spark/blue light coming from the front, then it does.